Burner



Sept. 5, 1933. P M FORSTER 1,925,183

BURNER Filed April 25, 1932 Patented Sept. 5, 1933 `UNITED STATES PATENT OFFICE Standard Oil Uompany of California,

a corporation of Delaware Francisco, Calif.,

San

Application April 25, 1932. Serial No. 607,329

6 Claims.

This invention relates to gas burners or torches and is particularly directed to portable burners such as may be used for burning paint, disinfecting poultry houses, stables, fox farms, etc., singeing poultry or hogs or for general heating purposes, especially Where the name is to be played over surfaces of considerable area. It is particularly adapted for use with liquefied petroleum gas such as propane, butane and the like, and in combination with a cylinder or bottle of such liqueed gas it constitutes a'n eiiicient and readily portable heater.

A customary form of torch or burner of this nature and heating capacity directs a conical or substantially cylindrical llame from its end. In the heating of extended surfaces such as are encountered in the removing of paint by burning, or the disinfecting of buildings such as poultry houses, stables and the like, these small flames, whose effects are localized due to their shape, require constant attention on the part of the operator in order to prevent local overheating and to obtain uniform ame contact.

. A further disadvantage to the torches and burners used heretofore is that they are not readily portable. Small hand torches, which are supplied by a normally liquid hydrocarbon such as gasoline, usually combine the storage tank with the burner in one unit and consequently are either clumsy and heavy to handle or require frequent relling, which is annoying and oftentimes dangerous. This improved burner, Lwhen used with a portable bottle of liquefied petroleum gas and a flexible metal or rubber hose, provides a means for eiicient and uninterrupted heating especially adapted to extended surfaces.

An object of this invention is to provide a burner of the air induction type in which a source of compressed air is not required for efficient combustion and the production of intense heat.

Another object is to provide a torch or burner in which the source of primary air may becontrolled and adjusted to suit the conditions of gas pressure and flame size required.

Another object is to provide a torch which will direct a broad :dat flame so that extended surfaces may be readily and uniformly heated with a minimum of attention on the part of the operator.

A further object is to provide a burner construction which will be simple, economical and easy to manufacture and in which adjustments for name size and gas consumption may readily be made.

Various other objects and advantages will be more fully apparent'from the following description and drawing which illustrates a preferred embodiment of this invention.

Because of the factthat the pressure of the liquefied hydrocarbon gases may be on the order 6@ of 20 to 150 pounds per square inch, the customary air induction burners designed for low pressures are not suitable for use with this gas. Most of these burners are of the customary Bunsen type in which the gas emerges from a small @5 orice or nozzle and is directed into the center of a single large diameter Venturi tube or its equivalent. The aspirating effect of the gas is used to draw in as much air as possible through the large flared inlet end of the Venturi tube. 7@ No provision is made for the introduction of secondary air, which has been found essential to secure complete and ecient combustion in large torches when burning high heat value gas under high pressure.

In other words, conventional burners larger than the customary laboratory type, which are of the construction suitable for natural or artificial gas of low heat value, are not adapted to be used with liqueed petroleum gas, nor are they capable of producing a fiat fan-like name which latter is quite useful for the purposes outlined above. It will be evident from the drawing and description that the burner of the present invention is a radical departure from the general type of air induction burners. It is provided with a primary or premixing tube of very small diameter as compared with the usual practice. This tube is flattened at the end to form what is here designated as a concave slot. In other words the slot is wider at its end than in the middle, as will be illustrated in the drawing accompanying this specification.

The external shield or director surrounds the primary mixing tube and is so shaped and perforated that a completely balanced flame in the shape of a fan and with a substantially nat front or edge is produced.

The accompanying drawing, which forms a part of this specification, show a preferred em- 100 bodiment of a torch or burner embodying the essential features of this invention. y.

In this drawing-Figure 1 represents a side view, partially in section, of a burner constructed according to this invention. A

Figure 2 is a side and part sectional view taken at right angles to the burner shown in Figure 1.

Figure 3 is an end view of the burner shown in Figures 1 and 2.

Referring to Figure 1, the numeral 10 represents 110 the body of the burner, which may be made from cast bronze or aluminum. The base of the body is provided with two arms or struts 1l which support a cylindrical boss 12. The boss 12 is threaded internally to receive the threaded end of a pipe 13 which extends through the boss and for a short distance between the arms 11. This latter distance may be adjusted by turning the threaded pipe' 13 in the boss 12 and maintained in adjustment by means of the lock nut 14. The end of the pipe 13 is reduced in diameter by swaging or brazing to form a small diameter nozzle 15 through which the gas emerges as a small' high velocity jet, and in this condition enters the body of the burner along with the primary air which it inspirates. The nozzle pipe 13 may be provided with a throttle valve (not shown) and is preferably connected by means of a flexible conduit to a source of liqueiied petroleum gas (not shown).

The body 10 of the burner may be formed with a circular closure disk 16 to which the arms 11 are joined. The external shield or fiame director 17 extends from the opposite side of disk 16 and may be cylindrical in section for a short distance out from the point of union with the disk section 16. From this point the shield 17 is fiattned and ared outwardly and its curvature is altered until at the tip of the burner it assumes the elliptical shape best illustrated by Figure 3. A plurality .of symnetrically spaced secondary air ports or holes 18 areV provided in shield 17 to supply secondary air to the space on both sides of the primary mixing tube which will be described later.

A threaded hole 19 is provided in the center of the circular closure disk section 16 of the body of the burner directly opposite and concentric with the nozzle 15 of .the gas inlet pipe. A primary mixing tube or nozzle 20 is screwed into hole 19 and may be held in relation to shield 17 by 'being expanded or upset at the end 2l. The outer end of tube 20, which is preferably formed by casting, is widened and ilattened to form a long narrow slot 22. The ends of the slot 22 are preferably cut back or recessed for a short distance back from the face as is illustrated at 23. The purpose of this recess is to prevent the high pressure gas iiame blowing out as readily as it would otherwise do if the recess were not there. Slot 22 is preferably made narrower in the center than at the ends in order that the mixture and the distribution of gas from the elliptical end of shield 17 may be such as to .produce a flame with a substantially at or square face. A descriptive term for this feature could be a concave slot. The desirability of such a uniform flame distribution is readily apparent when extended surfaces are to be momentarily heated.

It will be apparent that the amount of primary air aspirated by the nozzle 15 into the entrance of the primary mixing tube 20 may be varied as desired by loosening the lock nut 14 and screwing the threaded portion of the gas supply pipe 13 in or out of the threaded boss 12. The size of the flame and the rate of gas consumption may be altered by substituting tips having various sized oriflces.

As an example of this invention a torch was constructed with an outer shield 17 approximately 21/2 inches in diameter at the bottom and 5 inches long. This was ilattened to give an elliptical opening approximately 41/2 inches long and 1 inch wide at the center. The secondary air ports were located 1% niches, 2% inches, 3% inches, and 4 inches from the tip of the shield in the arrangement shown. The four central ports were approximately 11A, inches apart across the center line of the shield.

The gas supply pipe was 1A inch inside diameter and was swaged to a 11g inch diameter nozzle. The primary mixing tube was M4 inch inside diameter and 3% inches long. Its outermost end was flattened to be 11/ inches wide and the slot at its tip was approximately 1/8 inch wide at its ends and 11; inch wide at the center. The recess was cut approximately 335 inch back from the end of the mixing tube.

It will be apparent that certain modifications and changes could be made in this arrangement without departing from the essential features of the invention which embrace all changes, variations, and substitutions coming within the scope of the appended claims.

I claim:

1. A burner for hydrocarbon gas comprising a metal shield having a substantially cylindrical closed base and a flattened open end, air ports through said shield, an orifice in said base, a tube in said orifice extending into the flattened portion of said shield and having a ilattened slotted end, and a nozzle for directing a jet of gas into said tube.

2. A burner for hydrocarbon gas as described in claim 1 in which the nozzle is adjustable with relation to the said orifice.

3. A burner for hydrocarbon gas comprising a metal shield having a substantially closed base and a flattened open end of substantially elliptical cross-section, air ports through said shield, an orifice in said base, a tube in said orifice extending into the attened portion of said shield and having a ilattened slotted end of concave crosssection, and a nozzle for directing a jet of gas into said tube.

4. A burner for hydrocarbon gas as described in claim 3-in which the slotted end of concave crosssection of the tube is recessed at its extremities.

5. A burner for hydrocarbon gas characterized by a small diameter tube into which the primary air for combustion is inspirated by a jet of gas. the end of said tube being flattened to form a concave slot, and an enclosing fan-shaped directe ing shield surrounding said tube and having an elliptical open end with the major axis of said ellipse parallel to the slot in said tube.

6. In a burner for hydrocarbon gas, a small diameter tube into which the primary air for combustion is inspirated by a jet of gas, the end of said tube being attened to form a concave slot, and an enclosure for said tube adapted to admit secondary air for combustion and shaped to direct the resulting flame in a substantially at wide sheet axially from the end of the burner.

PERCY M. FORSTER. 

